GB2049516A

GB2049516A - Roll strands for rolling materials in web form

Info

Publication number: GB2049516A
Application number: GB8015649A
Authority: GB
Original assignee: Escher Wyss AG
Current assignee: Sulzer Escher Wyss AG
Priority date: 1979-05-10
Filing date: 1980-05-12
Publication date: 1980-12-31
Also published as: CA1119443A; DE2919748A1; US4319522A; IT8021847A0; AT369063B; ATA362979A; GB2049516B; DE2919748C2; IT1131440B

Description

1 GB 2 049 516 A 1

SPECIFICATION

Roll stands for rolling materials in web form This invention relates to a roll stand for rolling 70 materials in web form, the stand comprising a frame, at least one control led-def 1 ection roll having a beam secured in the frame, and a shell rotatable about the beam and supported on the beam by way of pressure elements to form a pressing force acting on a co-operating roll, the shell being movable along its entire length with respect to the beam in the roll pressing direction, in order to perform radial move ments.

A roll stand of this construction has been de- 80 scribed in, for example, German Offenlegungsschrift 26 51 028, in which the roll used has a beam movable so as to perform radial movements, and has also been described in United States Patent Specification

3 885 283. In the stand described in the German Offenlegu ngssch rift 26 51 028, this roll co-operates with a control led-def lection roll of the construction described in United States Patent Specification 3 802

044, and in which the shell is not mounted to be bodily movable in the pressing direction of the roll with respect to the beam, but is mounted in rolling bearings on the beam. Two types of control leddeflection rolls of this construction have hitherto been used in the construction of deflection-free roll stands, e.g. calenders for smoothing webs of paper, one such type - with the movable shell for the radial movements - being used for pressing and lifting while the other was used as a fixed co-operating roll to form a fixed point.

According to the present invention, a roll stand for 100 rolling materials in web form comprises a frame, a control led-def lection roll, and a co-operating roll, the control led-def lection roll having a beam secured in the frame, and a shell rotatable aboutthe beam and supported on the beam byway of pressure elements 105 to form a pressing force acting on the co-operating roll, the shell being movable along its entire length with respect to the beam in the roll pressing direction, in order to perform radial movements, and the shell of the control led-def lection roll being supported in the pressing position on abutments which are fixed with respect to the frame.

With this construction, a roll which has a shell movable in the pressing direction with respect to the beam becomes a roll in which the shell is fixed on the beam in the pressing direction, in a similar mannerto a roll in which the shell is fixed on the beam. Consequently, a single roll type can be used in the stand, while if the stand has two or more controlled-deflection rolls different effects can be obtained by one or other of the rolls being suitably actuated to convert itto a fixed roll, i.e. a roll with a fixed shell axis. Of course, the use of a roll con structed in accordance with the invention with a shell movable in the pressing direction is not restricted to the use of a control led-def lection roll as the co-operating roll. One or more co-operating rolls may be constructed as conventional solid rol Is, one of them being held fast and serving as a fixed roll or else all the rolls can be freely movable in a 130 pressing plane. In that case, given a vertical arrangement, their deadweight can form the pressing force, the control led-def lection roll acting as the fixed reaction roll.

Preferably, the shell is guided on the beam in the pressing direction by means of parallel guides on the shell and the beam respectively adjacentthe ends of the shell, the abutments are carried by the beam adjacent the guides on the beam, and the shell has corresponding abutments adjacent the guides on the shell. This is a very simple realization of the principle of the invention, since the surfaces already present in the roll described in United States Patent Specification 3 885 283 can be used as abutments.

There may also be provided means for adjusting the magnitude of the abutment forces by which the shell is supported on the abutments. To this end, the abutments may be provided with force measuring means for measuring the magnitude of the abut- ment forces by which the shell bears on the abutments, the force measuring means controlling the adjusting means.

It is particularly advantageous if the abutment forces act on the roll shell in the same direction as the pressing forces of the pressure elements. In such a case, the largest possible radial movement of the shell is available for opening the roll system. Of course, the abutment forces may also act in the opposite direction, in which case, given a roll with parallel guides, the shell bears on the opposite ends of the guides.

Preferably, the co-operating roll or one of a plurality of co-operating rolls can also be a controlled-deflection roll having a shell which, for performing radial movements, is movable in the pressing direction over its full length while also being rotatable with respect to a fixed beam. In such cases, the stand comprises two similar or identical controlleddeflection rolls which press against one another and one of which is used as a fixed roll.

Piston and cylinder units may be provided to form the abutment force and are situated at the ends of the roll shell near the guides. In such a case, the abutment forces act at the ends of the shell and do not affect its deflection.

The controlled-deflection roll may have pressure elements between the beam and the shell to form the abutment force. Preferably, the pressure elements used to form the abutment force are also used to form the pressing force, their force being increased beyond the pressing force value by the amount required to form the abutment force. This also gives a very simple construction of the stand, since no additional elements are required inside the roll to form the abutment force.

The invention may be used in a calender for smoothing paper webs. It may, however, be applied to roll stands for the treatment of other materials in web form, e.g. textiles, plastics or metal.

The supporting elements are preferably hydrostatic supporting elements with a hydrostatic shell mounting in the manner described in the United States Patent Specifications 3 802 044 and 3 885 283 mentioned hereinbefore.

The invention may be carried into practice in 2 GB 2 049 516 A 2 various ways but one roll stand embodying the invention and a number of modifications will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:

Figure 1 is a vertical transverse section of the rolls of a roll stand in the pressing position; Figure2 shows the roll stand of Figure 1 in the open position; Figure 3 is a diagrammatic partial section of one of the ends of the bottom control led-def lection roll of 75 the stand shown in Figures 1 and 2, in the open position as seen in Figure 2; Figure 4 is a section similarto part of Figure 1 showing a possible modification to the roil stand shown in Figures 1 to 3; Figure 5 is a section similar to part of Figures 1 and 2 showing another possible modification in which the roll stand comprises only one controlled deflection roll and two solid rolls freely movable in the pressing direction; Figure 6 is a circuit diagram of another roll stand having some similarity to that shown in Figures 1 to 3 but comprising two control led-def lection rolls and two solid rolls and with the hydraulic support pistons of the bottom control led-def 1 ection rolls arranged in groups; Figure 7 is a section similarto part of Figure 1, showing another possible modification of the bot tom roll; and Figure 8 is an end elevation of the bottom roll of another roll stand similarto that shown in Figures 1 to 3, this bottom roll acting as a fixed roll during operation.

Figures 1 to 3 show a roll stand comprising a top control led-def lection roll 1, a bottom controlleddeflection roll 2, and intermediate rolls 3, 4 and 5. The rolls 1 and 2 are of the construction described in United States Patent Specification 3 885 283. The rolls contain hydrostatic supporting pistons (shown in broken lines), which are pressed against the inner surface of a shell 8 by a hydraulic pressure fluid operative in cylinder chambers 7. Each of the pistons 6 may have a hydrostatic bearing surface facing the shell 8, as described in United States Patent Specifi cation 3 802 044, which has already been mentioned.

Each of the rolls 1 and 2 comprises a beam 10 which, as shown in Figure 3, is borne at its ends in side parts 11 of a frame so as to be pivotable but secured against rotation.

As will be seen from Figure 3, for this purpose the 115 ends 12 of the beam are each provided with a spherical mounting 13. At one of its ends the beam is secured against rotation in the side member by means of a pin 14.

As will also be seen from Figure 3, the ends of the shell contain guide members 15 on which the shell 8 is mounted in rolling bearings 16. The guide mem bers 15 have parallel guide surfaces 17 co-operating with corresponding parallel guide surfaces 18 on the beam 10, with which they form parallel guides. The parallel guides 17,18 of the rolls 1 and 2 are so disposed as to allow movements of the shells in the roll pressing direction, these movements lying in a pressing plane E (see Figure 2). As shown by double arrows 20 in Figure 1, the intermediate rolls 3,4 and are also freely movable in this plane E to an extent limited by stops (not shown).

As indicated diagrammatically in Figure 1, the hydrostatic pressure elements 6 of the rolls 1 and 2 are fed by a hydraulic pump 21, through a delivery line 22 and branch lines 23 and 24 which extend to the rolls 1 and 2 respectively. Branch line 23 contains a control valve 25 which reduces the pressure of the hydraulic fluid from line 22 to a value determined by a set-value signal 26. The resulting pressure in the branch line 23 is in this example fed to all the cylinder bores 7 of the roll 1. Similarly the branch line 24 leads to all the cylinder bores 7 of the pistons 6 of the roll 2. The distribution may, for example, be made via a bore 27 in the beam 10, as shown in Figure 3.

Branch line 24 contains a pressure control valve 28 having a differential pressure controller. The latter receives, via a signal line 28', a signal corresponding to the pressure in the line 23. At the same time, the controller receives a set-value signal 30, which determines the differential pressure by which in this case the pressure in the line 24 is to exceed the pressure in the line 23. The differential pressure determined by the set-value 30 is used to compensate for the deadweight of the moving parts of the rolls 1 and 2 and of the intermediate rolls 3 to 5, and to determine the abutment forces by which the end face 31 of the aperture 34 of the guide member 15 is pressed against the corresponding surface 33 of the beam 10 in Figure 1.

Loading of the roll system by influencing the set-value 26 takes equal effect in both rolls 1 and 2, butthe counteracting force formed by the bottom roll 2 is greater by the amount determined bythe set-value 30. The shell 8 of the bottom roil is in these conditions fixed by the surfaces 31 and 33 bearing one upon the other, so that the roll 2 operates as a fixed roll immovable in the pressing direction.

Since, in the example shown in Figures 1 and 2, the abutmentforces on the roll shell 8 of the bottom roll act in the same direction as the pressing forces of the pressure elements 6, i.e. in the upward direction, the entire length of the parallel guides 17, 18 is available for opening the roll stand. As will be seen from Figure 2, the shell 8 of the bottom roll 2 can be lowered until the end faces 3Vand 33'come into contact with one another atthe other end of the parallel guide. Gaps S thus form between the shells of the rolls 1 and 2 and the intermediate rolls 3 to 5, and these gaps are defined by abutments (not shown) in the mountings of the intermediate rolls 3, 4 and 5.

Referring to Figures 1 and 2, the abutment forces of the roll 2 are formed by a surplus force of all the pressure elements of the roll 2. - However, in the construction shown in Figure 4, the biassing force by which the surfaces 31 and 33 press on one another is formed by an auxiliary piston and cylinder unit comprising a piston 35 guided in a cylinder bore 34 in the beam 10. Cylinder 34 is connected to the delivery line 22 of the feed system 21 via an additional branch line 36 containing a pressure control valve 37. This valve determines the pressure in the line 36 in dependence on a I- 3 GB 2 049 516 A 3 set-value signal 38, and thus determines the pressure force by which the piston 35 is pressed against the end face 31' of the guide aperture 32 and hence by which the surfaces 31 and 33 are pressed on one 5 another.

In the construction shown in Figure 4, the surface 31 carries a forcemeasuring device 40 from which a signal line 41 leads to the controller of the pressure control valve 37. The controller adjusts the pressure in the branch line 36 by means of its valve so that the abutment force acting on the device 40 corresponds to the required set value 38.

Figure 6 is a diagram showing a roll system in which not all the pressure elements are used to form the abutment forces; only the groups of pressure elements at the end zones of the rolls are used. For the sake of clarity, like parts in Figures 1 to 3 and Figure 6 have been given like references.

The roll system shown in Figure 6 contains only two intermediate rolls 3 and 4 in addition to the two control led-def lection rolls 1 and 2. The pressure elements 6 of the roll 1 receive the same pressure from branch line 23 as in the construction shown in Figures 1 and 2. For the sake of clarity, the valve section 25' of the pressure control valve 25 has been shown separately.

In the construction shown in Figure 6, a signal line 42 leads from the pressure controller 25 to the pressure controller 28, which also receives a set- value signal 43, and from which an output line 44 leads to valve 28'. A signal line 45 branches from line 44 to a controller 46 which also receives a set-value signal 47. An output line 48 leads from the controller 46 to two valves 46'.

As will be seen from the bottom part of Figure 6, - the controller 46 together with the valves 46'it controls influences two groups a of pressure elements which are respectively located in the two end zones of the roll 2. The controller 28 with the valve 28', on the other hand, influences the rest of the pressure elements, i.e. the pistons 6 of a central group b situated between the two end groups a.

In the example shown in Figure 6, the two controllers 28 and 46 are differential pressure con- trollers. They so influence their valves 28'and 46' that the pressure in the respective lines is in each case greater than the value fed via the signal line 42 or 45 respectively, by an amount equal to the value introduced by the set-value signals 43 and 47 respectively. Set-value signal 43 has the function of compensating for the deadweight of the moving parts of the rol Is 1 and 2 and of the rolls 3 and 4. Set-value signal 47 additionally forms the abutment forces in the end zones of the roll 2. Thus in this case it is not all the pressure elements that are used to form these abutment forces, but only those of groups a.

Figure 7 is a detail of a possible modification to the roll 2 in Figure 1, in which the end face 31 is provided with a resilient buffer 50 against which the surface 33 of beam 10 acts. This provides a resilient abutment instead of a hard metal abutment.

Figure 8 shows another possible modification in which an external weightloaded mechanism is used to form the abutment forces. Referring to Figure 8, a link 52 is braced against the guide member 15 by means of a pin 51, the link being loaded by a weight 54 via a two-armed lever 53. The weight 54 is so dimensioned as to press the surfaces 31 and 33 on to one another by a required biassing force.

Of course, other modifications may be made to the constructions already described. For example, the control led-def lection rolls may have pressure elements of a type other than that described in the said United States Patent Specification 3 802 044. The controlled-deflection rolls may have a number of groups of pressure elements controllable independently of one another, in which case a hydraulic circuit similar to that shown in Figure 1 would be provided separately for each group.

In the embodiment shown in Figure 8, a hydraulic or pneumatic cylinder may be used instead of the weight 54.

Claims

1. A roll stand for rolling materials in web form and comprising a frame, a control led-deflection roll, and a co-operating roll, the control leddef 1 ection roll having abeam secured in the frame, and a shell rotatable about the beam and supported on the beam by way of pressure elements to form a pressing force acting on the co-operating roll, the shell being movable along its entire length with respectto the beam in the roll pressing direction, in orderto perform radial movements, and the shell of the control led-def lection roll being supported in the pressing position on abutments which are fixed with respect to the frame.

2. A roll stand as claimed in Claim 1 inwhichthe shell is guided on the beam in the pressing direction by means of parallel guides on the shell and the beam respectively adjacent the ends of the shell, the abutments are carried by the beam adjacent the guides on the beam, and the shell has corresponding abutments adjacent the guides on the shell.

3. A roll stand as claimed in Claim 2 which includes piston and cylinder units to form the abutment force, the units being situated at the ends of the roll shell near the guides.

4. Aroll stand asclaimed in Claim 1 orClaim 2or Claim 3 which includes means for adjusting the magnitude of the abutment forces by which the shell is supported on the abutments.

5. Aroll stand asclaimed in Claim 4in whichthe abutments are provided with force measuring means for measuring the magnitude of the abutment forces by which the shell bears on the abutments, the force measuring means controlling the adjusting means.

6. A roll stand as claimed in any of the preceding claims in which the abutment forces act on the roll shell in the same direction as the pressing forces of the pressure elements.

7. A roll stand as claimed in any of the preceding claims in which the control led-def lection roll has pressure elements between the beam and the shell to form the abutment force.

8. A roll stand as claimed in Claim 7 in whichthe pressure elements used to form the abutment force 4 GB 2 049 516 A 4 are also used to form the pressing force, their force being increased beyond the pressing force value by the amount required to form the abutment force.

9. A roll stand as claimed in any of the preceding claims in which the co-operating roll is also a control led-deflection roll having a shell which, for performing radial movements, is movable in the pressing direction over its full length while also being rotatable with respect to a fixed beam.

10. A roll stand as claimed in any of the preceding claims which forms a calender for smoothing webs of paper.

11. A roll stand substantially as described herein with reference to Figures 1 to 3 of the accompanying drawings.

12. A roll stand as claimed in Claim 11 modified substantially as described herein with reference to any one of Figures 4 to 8 of the accompanying drawings.

1 Printed for Her Majesty's Stationery Office by Croydon Printing Company Limited, Croydon Surrey, 1980. Published bythe Patent Office, 25 Southampton Buildings, London,WC2A lAY, from which copies may be obtained.

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